Field of the Invention
This invention relates generally to vehicle systems and control processes, such as railway systems including trains travelling in a track or rail network, and in particular to an arrival time and location targeting system and method that may be used in connection with navigation in railway networks, such as in connection with railway networks that include target locations (e.g., a crossing, a safety target, a track section, a track location, a specified location, a restricted speed location, a circuit, a restricted noise location, and the like).
Description of Related Art
Vehicle systems and networks exist throughout the world, and, at any point in time, a multitude of vehicles, such as cars, trucks, buses, trains, and the like, are travelling throughout the system and network. With specific reference to trains travelling in a track network, the locomotives of such trains are typically equipped with or operated using train control, communication, and management systems (e.g., positive train control (PTC) systems), such as the I-ETMS® of Wabtec Corp. In order to effectively manage all of the trains, navigation and enforcement systems and processes are implemented, both at the train level and the central dispatch level.
With respect to existing PTC systems and processes, targeting (i.e., prediction or determination of a future parameter) is based upon enforcing track speeds, restricted speeds, or stop targets. In particular, it is recognized that the targeting process of the on-board system is based on speed and braking predictor curves, and specific speed limits defined at single locations or location ranges. This does not lend itself to the concept of targeting based on when a train can arrive at a specific location in time. For example, with wireless crossing activation applications, the need for speed enforcement is secondary to the need for time enforcement. Due to the nature of a crossing, a certain amount of warning time must be realized before the train can safely traverse the crossing (or other target location). The existing targeting methodology does not account for changes in acceleration or deceleration, and does not enforce the warning and preemption times for the crossing. Instead, the methodology only enforces a set or specified speed.
For at least these reasons, there is a need in the art for an improved arrival time and targeting systems and methods. By creating and enforcing time-based targets, the train is permitted to change speeds as long as a target time or location is met, and the train will be warned or enforced to stop if it violates a specified target time or location.